Monsoon variability and high latitude climate signals in the Central Mediterranean at the Pliocene- Pleistocene transition: The Gelasian stratotype section (Monte San Nicola, Sicily) [Global and Planetary Change, volume 249, 104788]: Comment

The stratigraphic record of Monte San Nicola (southern Sicily, Italy), where the Global Boundary Stratotype Section and Point (GSSP) for the Gelasian Stage (Lower Pleistocene) has been defined, has been studied by our research group for fifteen years. In 2021, another working group (GELSTRAT) started investigating the Monte San Nicola stratigraphy in a location close to the GSSP section, with results that differ significantly from those published by our team. In particular, major discrepancies in the alkenone-derived paleotemperature reconstructions led the GELSTRAT team to suggest that our age model is invalid, and they inferred that we had made a wrong interpretation of the physical stratigraphic record. In this comment, we demonstrate that our chronological model is correct, while the stratigraphic profile studied by the GELSTRAT team should be approached with care, due to the presence of tectonic displacements, truncations, and uncertain lithological evidence for critical marker beds, such as the sapropel layers below the Nicola bed.